Type I diabetics undergoing pancreatic transplantation surgery will be studied pre-, immediately post surgery, and in longterm followup to (1) study the impact of physiologic regulation of glucose insulin kinetics and metabolic control (2) provide data on endocrine markers to identify early rejection of the transplanted pancreas; and (3) study the endocrine responses to various stimulatory tests on denervated, systemically drained, pancreas preparation.